This invention relates generally to pulse generators and is particularly adapted for providing high repetition rate pulse trains with rapid transition on leading and trailing pulse edges and having a readily controllable duty factor.
In many applications it is necessary to provide pulse trains of signals having a high repetition frequency, rapid pulse rise and fall times and substantial energy content. One example of such application is the pulse train used to drive the electro-optical switch in high pulse rate laser units. Prior approaches to producing such pulse trains include the discharging of a pulse forming network through a silicon controlled rectifier (SCR) and a pulse transformer to the load circuit. This approach has the disadvantage of no or minimal control of the duty factor of the pulses which are produced and is generally limited to producing pulse trains of relatively low repetition rates. Another approach which has been implemented to provide such pulse trains is to use transistors either as normal pulse amplifiers or in their avalanche mode to generate a signal which is transformer coupled to the load circuit. However, in accordance with this just mentioned technique the use of conventional transistors results in pulses whose rise and fall times are too slow for many applications, while the use of avalanche type transistor switches suffers from poor duty factor control and low repetition rates.